Presidential candidate Abdel Moneim Aboul Fotouh was riding in a car Thursday night when he was attacked, bikyamasr.com reported.
A gunman, who fled the scene, hit Aboul Fotouh over the head with a machine gun.
Aboul Fotouh and his driver, who was also injured in the attack, were taken to a hospital for treatment.
It was not clear whether the attack was a political hit or a robbery.
Aboul Fotouh, a former leader with the Muslim Brotherhood, has the best chance at winning the presidential election, scheduled for June, as he appeals to both liberals and conservatives alike across Egypt, experts said.